The climate crisis is often framed in terms of melting ice caps, rising seas, and increasingly frequent heatwaves. But beyond the rising temperatures, an invisible health emergency is unfolding. One not reflected in heat charts, but instead with issues with people’s hearts, lungs and brain function resulting in lives cut short.
In 2024, global temperatures breached the 1.5 °C threshold for the first time since the Paris Agreement was signed. It was also the hottest year ever recorded, capping a decade in which every single year ranked among the hottest on record.
The 2003 European heatwave alone claimed around 70,000 lives, including 14,800 deaths in France in just three weeks, and by 2050 those temperatures are projected to become average summer conditions in Europe. The 40 °C heatwave in southeast England in 2022 was 16 °C hotter than the decade’s average peak for July.
Around the world, climate-related mortality is climbing, and the burden of pollution and extreme weather is falling disproportionately on the poorest and most vulnerable. Older people are especially at risk: global heat-related deaths among those over 65 have risen sharply since 2010 due to more frequent heatwaves and ageing populations.1
This is not just an environmental problem; it is a public health emergency unfolding in real time. And it is one we can begin to solve in the short-term - if we act decisively.
Cutting emissions means better health, now
The science is unequivocal: reducing greenhouse gas emissions leads to cleaner air.
Cleaner air means fewer cases of asthma, heart disease, and strokes. It means children growing up with healthier lungs and older adults enjoying longer, more active lives. The health benefits of climate action are not a distant promise; they can be measured in months and years, not decades.
A recent meta-analysis found that each 1 °C rise in temperature increases kidney-related morbidity by 1% and mortality by 3%, meaning that every step we take to curb warming delivers measurable health gains.1
In the UK, phasing out coal has already slashed sulphur dioxide levels, improving respiratory health. In China, air quality improvements from clean energy policies have prevented hundreds of thousands of premature deaths. Around the world, these co-benefits are replicated wherever governments choose cleaner, healthier energy and transport systems.
Reframing climate action as a survival investment
We must stop treating climate action as a costly sacrifice for the sake of a future we may never see. It is, instead, an investment in survival, one that delivers near-instant returns.
By prioritising the health co-benefits of emissions cuts, policymakers can make the case for bolder, faster change.
And when we factor in the savings from reduced healthcare costs, fewer sick days, and more productive economies, climate action is not just morally urgent - it is economically prudent.
For example, one billion people still lack regular access to safe drinking water today, and without action, up to half the global population could live in water-stressed countries by 2050 - with 80% of those in developing nations.1 Addressing climate drivers now avoids the massive future costs of water scarcity, disease outbreaks, and malnutrition.
Health equity at the heart of climate policy
Climate change is the greatest threat multiplier of our time, exacerbating existing inequalities in health. Those with the fewest resources often live in the most polluted neighbourhoods, have the least access to healthcare, and are most exposed to climate-related hazards. If we fail to address this imbalance, we will entrench injustice even as we tackle emissions.
Food systems are already straining under climate pressures: over 730 million people are currently on the brink of starvation, with extreme heat and drought reducing staple crop yields and nutrient quality.1 Malnutrition undermines resilience, making communities even more vulnerable to climate-driven disease and disasters
Governments must design climate strategies that centre health equity, resilience, and burden reduction. This means investing in green public transport that serves deprived areas, retrofitting housing to protect against both heat and cold, and ensuring early-warning systems reach every household - not just those with the latest technology.
Winning public support through better health
Climate policy can feel abstract and politically polarising. But the promise of us all living longer healthier lives with cleaner safer neighbourhoods transcends ideology. Framing climate action as a health imperative could be the key to building lasting political will for the faster, fairer transition we need.
The evidence is clear: when we cut emissions, we can save lives and money in the short term. The question is not whether we can afford to act, but how many more lives we are willing to lose if we don’t.
1 Maslin, M., Ramnath, R. D., Welsh, G. I., & Sisodiya, S. M. (2025, March). Understanding the health impacts of the climate crisis. Future Healthcare Journal, Article 100240. https://doi.org/10.1016/j.mfuture.2025.100240
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